Modern passenger transport aircraft typically include one or more on-board galleys outfitted with one or more electrical power consuming devices, such as ovens, water boilers, coffee machines, trash compactors, and the like. A power line network or branched feeder system receives power from the electrical system of the aircraft and distributes the electrical power to the various connected electrical consuming devices. In this regard, the power supply or distribution network is designed and laid out, so that all of the connected electrical consuming devices of the on-board galley can be operated at full power, i.e. full load, at any desired time, which means that the capacity of the power distribution network must be sufficient to simultaneously provide full power to all of the electrical consuming devices. This is rather inefficient, because in actual practice, the simultaneous full-load utilization of all of the electrical consuming devices arises only rarely in exceptional situations.
Also, such a design and lay-out of the power distribution network requires that the total sum of the connected loads of all of the installed power consuming devices of the on-board galley must always be smaller than the available supply power or connection power of the respective galley power supply system. In other words, the power supply system and its components are laid out for the worst-case all-devices-at-full-load situation, even though this situation would arise only rarely, if at all. This results in unnecessary weight, complexity, and cost of the power supply system and its components.
Especially in future applications in aircraft, in which the number of installed electrical power consuming devices or loads will increase, the conventionally designed power supply and distribution networks will no longer be suitable and able to ensure that all electrical devices will be adequately supplied with electrical power from the available limited electrical energy supply on-board the aircraft. In the field of electrical power consuming installations in aircraft, it is always a critically important consideration, that the available supply of electrical power is strictly limited, rather costly, and always a trade-off with respect to other power consumption in the total energy budget of the operation of the aircraft.
In future situations involving a greater number of electrical devices, it could be attempted, for example, to provide mechanical selector switches that provide an “OR coupling” of two or more electrical devices, whereby always only one of the electrical devices may be selected for operation at any one time by mechanically actuating the selector switch. Alternatively, it would be necessary to provide additional power distribution lines to supply the additional required power to the on-board galley, but this would increase the total dead weight of the aircraft, and would also increase the cost and complexity of the power supply system and potentially over-crowd the spatially limited power supply conduits or raceways.
German Patent Publication DE 195 07 039 A1, as well as U.S. Pat. No. 5,637,933 disclose an energy or power supply system that comprises a power bus as well as several electrical consuming devices connected by connector arrangements to the power bus. Furthermore, the known system includes a control unit, which constantly monitors the electrical consuming devices, and can correspondingly react in the event a faulty or erroneous operation or malfunction of a given device is recognized. Particularly, in the event of a malfunction or erroneous operation, or in the event of an excessive power consumption, the control unit can switch off the electrical consuming device that has the lowest supply priority. For this purpose, each one of the electrical consuming devices is equipped with a configuration code transducer, which contains or provides, for example, an information regarding the type of the electrical consuming device as well as its priority in the power supply scheme. In the event a fault, error, or malfunction in the power source leads to a reduction of the available power being supplied, the control unit sends a signal to the corresponding associated power switch of the electrical consuming device having the lowest priority, so as to switch off this lowest-priority device and thereby reduce the total power consumption of the total electrical system.
Thus, according to the prior art, the only possibility for reducing the total power consumption of the electrical system is to completely switch-off or remove one or more devices from the power supply system. That, of course, significantly detracts from the functionality and user-friendliness of the kitchen devices installed in the galley, because one or more of the devices will become totally inoperable when the overall galley is operating at or near full electrical load. This is especially inconvenient for the users of the galley, because such situations of high electrical load can arise especially when the users of the galley rely on and need the full functionality of all of the devices, for example during meal catering phases of a flight of the aircraft. It is just at such high utilization periods that the flight attendants or other personnel using the galley may find that one or more of the electrical consuming devices in the galley have been automatically switched off to avoid a power overload.